Display panel for displaying numbers and words

ABSTRACT

The panel includes at least one large-area cathode and an associated large-area transparent conductive anode on the face plate of the panel spaced from the cathode. The anode has a metal strip extending along at least a portion of its periphery for increasing its conductivity and permitting it to operate properly at relatively high currents, and the cathode is a mesh, silkscreened cathode having considerable open area to reduce its surface area and its current requirement for full glow.

United States Patent Glaser [451 Oct. 1, 1974 DISPLAY PANEL FOR DISPLAYING NUMBERS AND WORDS David Glaser, Green Brook, NJ.

Burroughs Corporation, Detroit, Mich.

Filed: Dec. 26, 1972 Appl. No.: 317,885

Inventor:

Assignee:

C 2 3 14 /Z17-,.1 /1 .3. Int. Cl. H0lj 7/42 Field of Search 313/1095, 220, 217, 188,

References Cited UNITED STATES PATENTS 10/1967 Hardwick 313/1095 11/1972 Shesser 313/220 X /174 MEAT 250 RODUCE 3,720,452 3/1973 Kupsky 313/1095 X Primary Examiner-Nathan Kaufman Attorney, Agent, or Firm-Robert A. Green; Edward G. Fiorito; Paul W. Fish 5 7] ABSTRACT 12 Claims, 5 Drawing Figures 1 FRUIT QDAI RY PAIENIEHBBT Hm 3.839.655

sum m 2 MEAT 1 O FRUIT PRODUCE DAIRY F i g. 1 i l I i l U l i l l l E 190A 19OB F i g. 3

F i g. 4

1 QOC Fig.5

DISPLAY PANEL FOR DISPLAYING'NUMBERS AND WORDS BACKGROUND OF THE INVENTION Cold cathode gas-filled display panels are widely used in instruments such as electronic calculators for displaying numbers. Such panels, in general, are small and include groups of small-area cathode bars or segments, each having an associated anode. In such panels, since the cathode segments are relatively narrow and have a small surface area, only relatively small currents are required to achieve full cathode glow over the entire surface of a cathode.

However, in other panels of this type which are designed to display rather long messages or words (in ad dition to numbers), the word portion includes one or more large-area cathodes, one or more large-area anodes, and an associated message plate which carries the word or words which are illuminated and displayed by glow generated by one or more of the large-area cathode(s). It has been found that large-area cathodes of this type draw excessive current if the expedients of the present invention are not employed.

SUMMARY OF THE INVENTION Briefly, a display panel embodying the invention includes one or more large-area cathodes in the form of a mesh having considerable open area whereby the current required for full cathode glow is held at a favorable low level.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a display panel embodying the invention;

FIG. 2 is a perspective exploded view of the panel of FIG. 1;

FIG. 3 is a plan view of a modification of a cathode embodying the invention;

FIG. 4 is a plan view of another modification of a cathode embodying the invention; and

FIG. 5 is a plan view of still another modification of a cathode embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The display panel described herein is a thin, flat, sheet-like member which may have substantially any desired size and shape, and may include substantially any number of character display positions. The panel may also include any suitable ionizable gas such as neon, argon, xenon, etc., singly or in combination, with a vapor of a metal such as mercury usually included in the gas to minimize cathode sputtering. A wide range of gas pressures may be used, for example, from about to about 250 Torr at ambient temperature, with about 100 Torr being a pressure which is commonly used.

A display panel 10 embodying the invention includes a first portion 160 along its lower margin for displaying numbers and a second portion 170 along its upper margin for displaying words for use in association with the numbers of portion 160. A panel of this type couldbe used in association with a cash register in a supermarket to permit customers to see items and prices as the information is fed into the register by the checker.

The number-displaying portion of panel 10 may take any of a number of suitable forms such as those shown in copending applications Ser. No. 188,485, filed Oct. 12, 1971, Ser. No. 227,744, filed Feb. 22, 1972, and Ser. No. 173,854, filed Aug. 23, 1971. The preferred form is described and claimed in the lastmentioned application and is of the type known commercially as a PANAPLEX panel. However, other number-displaying panels could also be used. Accordingly, this portion of the panel is not shown in detail, but rather it is represented schematically.

Referring to FIG. 2, the portions 160 and of panel 10 are preferably formed on a single insulating base plate of glass, ceramic, or the like, with an inexpensive glass being suitable and preferred. Briefly, the portion 160 includes a plurality of groups of cathode electrodes 60, each cathode being connected through an apertured insulating layer (not shown) to a conductive run (not shown) beneath the insulating layer. Each cathode can be energized by the applica tion of potential to its conductive run.

The portion 170 of panel 10 includes a plurality of relatively large glow cathode areas for use in displaying the associated words 174. The number of words to be displayed and the number and size of the cathode areas 190 are a matter of choice, depending on the use to be made of the panel. In any case, the cathodes 190 are considerably larger in area than the cathode 60; and, in general, they require considerable current to cover their entire surfaces with cathode glow. According to the invention, in order to achieve full cathode glow with minimal cathode current, the cathodes 190 comprise apertured members in mesh form or the like, and they operate satisfactorily with fifty percent or more of open area. Such cathodes are preferably made by a silk-screen process, and each includes a tab or lead 200 to which electrical connection can be made. The cathodes 190 are formed directly on the surface of base plate 20, and tabs 200 may extend directly laterally to an edge of the base plate, or they may be bent and extend to the lower edge of the base plate 20, overlaying the above-mentioned insulating layer as shown.

An insulating spacer frame 210 is disposed on base plate 180, and the panel face plate 220 is seated on the frame 210. The face plate has substantially the same area as the base plate 180. The bottom surface of the face plate 220 carries an anode 90 for each of the groups of cathodes 60 and additional anodes 230 for the cathodes 190. The anode electrodes 90 and 230 comprise thin, transparent conductive films of NESA or the like formed on the lower surface 96 of the panel face plate or viewing plate 100 which is made of glass. The anode films 90 are generally rectangular in shape, and they are dimensioned and positioned so that each generally overlays the total area defined by its group of cathode electrodes 60. Each anode 90 has a contact portion 98 to which external contact is made. As illustrated, a separate anode 230 may be provided overlaying each large-area cathode 190, or one large-area anode 230' may cover two cathode areas. The anodes 230 may have approximately the same areas as cathodes 190. The optimum anode arrangement can easily be determined by those skilled in the art. The anodes 230 are provided with contact tabs 233 and 233 which may extend directly laterally as shown, or they may extend elsewhere, for example, to the lower edge of face plate 220 adjacent to anodes 90.

The resistance of the anodes 230 and 230', and particularly the leads of such anodes, can be of considerable magnitude, and, as a result, there can be a significant voltage drop across the leads. Such a voltage drop can adversely effect the relationship between the rest of the anode and the associated cathode 190, with the result that the cathode may exhibit only partial glow. To avoid this problem, a metallic border 240 is provided around all or a part of each anode 230 and its lead 233, as described and claimed in copending application Ser. No. 303,991, filed Nov. 6, 1972.

The three glass members 180, 210, and 220 are sealed together along their adjacent edges in any suitable manner, for example, by means of a glass frit or the like (not shown).

The panel 10 includes a message-carrying plate 250 which carries the desired message 174 in any suitable form. The plate 250 may be cemented or otherwise secured to the top surface of face plate 220 in proper alignment over the cathodes 190.

The panel 10 can be filled with the desired gas atmosphere through a tubulation (not shown) secured to the base plate 180 and communicating with the interior of the panel through a suitable hole in the base plate, and, generally, mercury is introduced from a glass capsule (not shown) held in the tubulation and suitably processed at the desired stage in the assembly process.

Electrical connections to the cathode runs, anode tabs 98, and anode tabs 233 and 233' are made in any suitable manner. As an example, pins (not shown) may be embedded in the seal between the various plates or spring-like connectors (not shown) can be used as shown and claimed in copending application Ser. No. 201,655, filed Nov. 24, 1971.

The cathodes of the invention may be modified in many ways to achieve large-area glow with low current. For example, as shown in FIG. 3, cathodes 190A might comprise a plurality of horizontal lines with connection lines at the ends and perhaps at the middle. In another arrangement shown in FIG. 4, a cathode 1908 might be in spiral form, and another cathode 190C shown in FIG. 5 comprises a spiral having generally rectangular legs and two cross lines.

In operation of panel 10, as the operator manipulates a cash register or other data source, signals are coupled therefrom to apply operating potentials between the appropriate anode 90 and cathodes 60 to display the proper numerical representation. This operation is performed in a multiplexing mode in which each group of cathodes and its associated anode are turned on sequentially at a suitable rate to provide an apparently stationary display. At the same time, the appropriate signals are applied to the proper anode 230 and cathode 190 to display the associated product message 174.

What is claimed is:

1. A display panel comprising a gas-filled envelope including a base plate and a face plate spaced apart from each other and hermetically sealed together along a common perimeter,

at least one large-area cathode electrode disposed adjacent to said base plate, said cathode electrode comprising a plurality of spaced-apart conductive members which are all electrically connected together, the individual conductive members being so positioned with respect to adjacent conductive members that when the cathode is electrically energized, the glow from the members blends to form a relatively large area of cathode glow,

a conductive film anode disposed on the inner surface of said face plate overlaying said cathode electrode, and

a message-carrying member spaced from and overlaying said' large-area cathode and adapted to have its message rendered visible by glow passing therethrough from said large-area cathode.

2. The panel defined in claim 1 wherein said cathode has the form of a mesh.

3. The panel defined in claim 1 wherein said cathode has the form of a mesh having at least 50 percent of its area open.

4. The panel defined in claim 1 wherein said cathode electrode comprises a plurality of conductive parallel horizontal lines.

5. The panel defined in claim 1 wherein said cathode electrode comprises a plurality of conductive parallel horizontal lines and having vertical lines in contact with and crossing said horizontal lines at their ends and at about their centers.

6. The panel defined in claim 1 wherein said cathode is in the form of a spiral.

7. A display panel comprising a gas-filled envelope including a base plate and a face plate spaced therefrom, said face plate including a viewing window,

a first number-displaying portion on said base plate and disposed along a first margin thereof,

a second word-displaying portion on said base plate and disposed along a second margin thereof,

said first portion comprising a plurality of groups of relatively narrow, small-area cathode segments disposed in a line side-by-side,

a transparent anode electrode on said face plate aligned with each of said groups of cathode seg ments,

said second portion comprising a plurality of largearea cathode electrodes disposed on said base plate, said large-area cathodes having open, nonconductive surface portions,

an anode electrode on said face plate for each largearea cathode, and

a word-carrying message plate disposed on said face plate with the words carried thereby aligned over said large-area cathodes and adapted to be rendered visible by cathode glow therefrom.

8. The panel defined in claim 7 wherein each of said large-area cathode electrodes has the form of a mesh.

9. The panel defined in claim 7 wherein each of said large-area cathode electrodes has the form of a mesh having at least 50 percent of its area open.

10. The panel defined in claim 7 wherein each of said large-area cathode electrodes comprises a plurality of conductive parallel horizontal lines.

11. The panel defined in claim 7 wherein each of said large-area cathode electrodes comprises a plurality of conductive parallel hoirozintal lines and having vertical lines in contact with and crossing said horizontal lines at their ends and at about their centers.

12. The panel defined in claim 7 wherein each of said large-area cathode electrodes is in the form of a spiral. l 

1. A display panel comprising a gas-filled envelope including a base plate and a face plate spaced apart from each other and hermetically sealed together along a common perimeter, at least one large-area cathode electrode disposed adjacent to said base plate, said cathode electrode comprising a plurality of spaced-apart conductive members which are all electrically connected together, the individual conductive members being so positioned with respect to adjacent conductive members that when the cathode is electrically energized, the glow from the members blends to form a relatively large area of cathode glow, a conductive film anode disposed on the inner surface of said face plate overlaying said cathode electrode, and a message-carrying member spaced from and overlaying said largearea cathode and adapted to have its message rendered visible by glow passing therethrough from said large-area cathode.
 2. The panel defined in claim 1 wherein said cathode has the form of a mesh.
 3. The panel defined in claim 1 wherein said cathode has the form of a mesh having at least 50 percent of its area open.
 4. The panel defined in claim 1 wherein said cathode electrode comprises a plurality of conductive parallel horizontal lines.
 5. The panel defined in claim 1 wherein said cathode electrode comprises a plurality of conductive parallel horizontal lines and having vertical lines in contact with and crossing said horizontal lines at their ends and at about their centers.
 6. The panel defined in claim 1 wherein said cathode is in the form of a spiral.
 7. A display panel comprising a gas-filled envelope including a base plate and a face plate spaced therefrom, said face plate including A viewing window, a first number-displaying portion on said base plate and disposed along a first margin thereof, a second word-displaying portion on said base plate and disposed along a second margin thereof, said first portion comprising a plurality of groups of relatively narrow, small-area cathode segments disposed in a line side-by-side, a transparent anode electrode on said face plate aligned with each of said groups of cathode segments, said second portion comprising a plurality of large-area cathode electrodes disposed on said base plate, said large-area cathodes having open, non-conductive surface portions, an anode electrode on said face plate for each large-area cathode, and a word-carrying message plate disposed on said face plate with the words carried thereby aligned over said large-area cathodes and adapted to be rendered visible by cathode glow therefrom.
 8. The panel defined in claim 7 wherein each of said large-area cathode electrodes has the form of a mesh.
 9. The panel defined in claim 7 wherein each of said large-area cathode electrodes has the form of a mesh having at least 50 percent of its area open.
 10. The panel defined in claim 7 wherein each of said large-area cathode electrodes comprises a plurality of conductive parallel horizontal lines.
 11. The panel defined in claim 7 wherein each of said large-area cathode electrodes comprises a plurality of conductive parallel hoirozintal lines and having vertical lines in contact with and crossing said horizontal lines at their ends and at about their centers.
 12. The panel defined in claim 7 wherein each of said large-area cathode electrodes is in the form of a spiral. 